Flexible Base Structure for Portable Shelters

ABSTRACT

An example method for providing a flexible base structure for a portable shelter includes the steps of forming a continuous loop of a flexible material and attaching a plurality of rib intersections at respective locations along the flexible loop. An alternative method for constructing a flexible base structure for a floorless portable shelter includes forming a continuous loop of a flexible material and arranging a plurality of openings at respective locations along the continuous loop. An embodiment of a base structure for supporting the ribs of a portable shelter includes a flexible loop and a plurality of rib intersections arranged along the flexible loop. Each of the plurality of rib intersections forms an opening for receiving a respective end of a rib that supports the portable shelter.

BACKGROUND

Outdoor portable shelters such as tents have been used to providetemporary shelter and protection from the sun, wind, precipitation,harsh temperatures, condensation, biting insects, and other outdoorelements for workers, equipment, and outdoor enthusiasts for many years.Aside from protecting an interior volume from the elements, modern dayshelters should be quick to set-up and portable. To be portable, thetemporary shelter should be lightweight so it is easily carried to aproposed site as well as easy to assemble and disassemble.

Most conventional tents are configured with a floor that is made of aheavier material than that used for the portions of the tent that willnot be in contact with the ground. The weight of the heavier materialused to construct the floor of these tents makes up a significantportion of the overall weight of the tent. The floor is often configuredwith loops at fixed locations along the perimeter of the tent forreceiving a stake that sets or fixes the floor of the tent to theground. These floors are often configured with additional hardware andor loops for locating and receiving an end of a flexible support rib.Once all the support ribs are flexed and set at their designatedreceiving ends in or near the perimeter of the floor, the upper panelsof the tent can be supported from the ribs. Some conventional tents usesleeves formed or otherwise attached to the outer surface of the upperpanels of material to suspend the tent. Other conventional tents usehooks connected to tabs or other extensions that are sewn to the upperpanels of the tent to suspend the tent under the support ribs. Many ofthese conventional tents use a rain fly to further shelter the tent.

A rain fly protects the tent from harmful ultraviolet radiation from thesun. In addition to protecting the tent from the sun, a rain flyprovides an additional barrier in the rain and snow, can help keepsparks from a fire or wood stove away from the exterior surface of thetent and when set up correctly can provide an insulating layer when itis cold. Conventional rain flies are made from a relatively lightweightfabric made from man-made fibers (e.g., nylon, polyester) with canvasties or other heavier fabrics used together with hook and loop fastenersfor fixing the rain fly to support ribs. The fabric is often treated orcoated with various waterproofing and fire resistant agents. Whenappropriate, a hole for a stove jack or vent will be formed with canvasor reinforced webbing.

Some outdoor enthusiasts prefer to travel with as little gear aspossible. For example, some hikers and climbers when faced withtransporting food, water, fuel, a sleeping bag and roll, a portableshelter and perhaps additional items including a community shelter formeeting, cooking, or other functions will elect to carry a relativelylightweight rain fly with the necessary support ribs rather than aconventional tent with a floor.

However, absent the orientation and resistance provided by aconventional tent with a floor, a lightweight rain fly or otherlightweight portable shelter without a floor can be difficult if notimpossible to set-up by oneself. Setup of a lightweight cover, such as arain fly, is problematic for at least the reason that it is difficult toalign and flex the various ribs into their desired orientation absentthe footprint provided by the floor of the corresponding tent.

Accordingly, it would be desirable to develop an apparatus and variousmethods that overcome these shortcomings.

SUMMARY

A flexible and scalable base structure for floorless portable sheltersand methods for constructing and using the same are invented anddisclosed.

One embodiment of a base structure for floorless portable sheltersincludes a flexible loop and a plurality of rib intersections arrangedalong the flexible loop, each of the plurality of rib intersectionsforming an opening for receiving a respective end of a rib. The flexibleloop is arranged in a length that enables each of the rib intersectionsto be positioned to receive a corresponding end of a rib or otherflexible member that supports the material of a rain fly or other coverin a desired configuration.

An alternative embodiment of a base structure for a floorless portableshelter includes a flexible loop having an adjustable length and aplurality of rib receiving members arranged along the length of theflexible loop. Each of the plurality of rib receiving members can bemoved along the length of the flexible loop. In this alternativeembodiment, an even number of the rib receiving members can be suitablypositioned to support any number of floorless portable shelters bysetting the length of the perimeter formed by the flexible loop andmoving each of the rib receiving members to an appropriate locationalong the flexible loop.

Another embodiment of a base structure for floorless portable sheltersincludes a flexible loop and a plurality of rib receiving membersarranged at fixed positions relative to each other along the length ofthe flexible loop.

An embodiment of a method for providing a flexible base structure for aportable shelter includes the steps of forming a continuous loop of aflexible material and attaching a plurality of rib intersections atrespective locations along the flexible loop.

An alternative embodiment of a method for constructing a flexible basestructure for a floorless portable shelter includes the steps of forminga continuous loop of a flexible material and arranging a plurality ofopenings at respective locations along the continuous loop.

Other devices, methods, features and advantages will be or will becomeapparent to one skilled in the art upon examination of the followingfigures and detailed description. All such additional devices, methods,features and advantages are defined and protected by the accompanyingclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

The flexible base structure for portable shelters, as defined in theclaims, can be better understood with reference to the followingdrawings. The components within the drawings are not necessarily toscale relative to each other; emphasis instead is placed upon clearlyillustrating the elements, features and principles involved insupporting the ribs or flexible poles of a fly, rain cover, or floorlesstent with the flexible base structure.

FIGS. 1 and 2 are schematic diagrams illustrating an embodiment of abase structure in relationship with an assembled portable shelter.

FIGS. 3 and 4 are schematic diagrams detailing the integration of asupporting rib and cover of a portable shelter at a select locationalong the base structure of FIGS. 1 and 2.

FIG. 5 is a schematic diagram illustrating the integration of asupporting rib of a portable shelter with an alternative base structure.

FIG. 6 is a schematic diagram illustrating the integration of asupporting rib of a portable shelter with a third alternative basestructure.

FIGS. 7-11 are schematic diagrams illustrating various alternativeembodiments of a base structure for portable shelters that integratewith three support ribs.

FIG. 12 is a schematic diagram illustrating a base structure forportable shelters that integrates with four support ribs.

FIG. 13 is a schematic diagram illustrating a portion of a basestructure having an adjustable length.

DETAILED DESCRIPTION

Flexible and scalable base structures for floorless portable sheltersand methods for constructing and using the same are invented anddisclosed. The base structures for floorless portable shelters arelightweight and enable a user to assemble easily a floorless portableshelter without the assistance of others.

The base structures include a primary loop that can be formed fromwebbing, rope, cable or wire or other lightweight materials that willnot stretch or shrink significantly over a range of temperature,humidity and in the presence of contaminants. In some configurations,the primary loop forms a fixed perimeter. In a first alternativeembodiment, a first end of webbing, rope or other materials is connectedto a strap or buckle that can receive the opposing end of the webbing,rope or other material to enable a user to form a primary loop with anadjustable length. In a second alternative embodiment, one or moresections or segments of the primary loop are arranged with respectivefriction lock collars that are fixed to respective ends of a wire orcable. The friction lock collars provide a mechanism for adjusting theperimeter of the flexible base structure.

Rib intersections are arranged at desired locations along the loop. Therib intersections receive respective rib ends (i.e., the ends of supportmembers) of the portable shelter to be constructed and supported usingthe base structure. In certain embodiments, a grommet is used to engagethe end of a rib. Some of the illustrated embodiments show the grommetdirectly embedded within the primary loop (i.e., in the webbing), whileother embodiments include a secondary loop with a respective grommet forreceiving and locating the rib ends. Embodiments that include asecondary loop can be arranged such that the secondary loop is at afixed location along the length of the primary loop. Alternatively, oneor more of the secondary loops can be configured to be moved along thelength of the primary loop.

Embodiments that use a secondary loop of sufficient size that surroundsthe primary loop can be twisted to align an opening for receiving andholding a respective rib end.

These arrangements can be constructed without grommets. A ribintersection can also be formed by a member with a channel for receivinga portion of the primary loop and a tab with a suitably sized hole forreceiving a rib end.

Having generally described the base structures for floorless portableshelters, various additional embodiments will be described in detailwith respect to FIGS. 1-13. FIG. 1 is an exploded front viewillustrating a portable shelter 10 above a base structure 100. Portableshelter 10 is supported by three ribs. A first rib end 20 a extendsbeyond the lower edge of panel 40 and the lower edge of panel 42 at theintersection of the panels. Rib 20 forms an arch that extends to anopposing side of the portable shelter 10 where rib end 20 b extendsbelow the lower edge of panel 34 and panel 36 at the intersection of thepanels. A second rib end 22 a extends beyond the lower edge of panel 42and the lower edge of panel 32 at the intersection of the panels. Rib 22forms an arch that extends to an opposing side of the portable shelter10 where rib end 22 b extends below the lower edge of panel 36 and panel38 at the intersection of the panels. A third rib end 24 a extendsbeyond the lower edge of panel 32 and the lower edge of panel 34 at theintersection of the panels. Rib 24 forms an arch that extends to anopposing side of the portable shelter 10 where rib end 24 b extendsbelow the lower edge of panel 38 and the lower edge of panel 40 at theintersection of the panels.

Panel 30, panel 32, panel 34, panel 36, panel 38, panel 40 and panel 42lie above rib 20, rib 22, and rib 24. Each of the panels is made from alightweight fabric made from man-made fibers (e.g., nylon, polyester).The panels may be treated with various sprays, solutions or other agentsto make the portable shelter 10 resistant to fire, wind and waterpenetration and damage from ultraviolet radiation. Each of the panels isconfigured with hooks, ties or hook-and-loop fasteners to keep thepanels correctly positioned above and in close contact with therespective ribs.

Unlike most conventional tents, portable shelter 10 is open to theground or surface that will support rib end 20 a, rib end 20 b, rib end22 a, rib end 22 b, rib end 24 a and rib end 24 b.

Panel 30 is located at the upper edge of panel 42 and between panel 40and panel 32. The edges of panel 42 are connected to panel 30 and one orboth of panel 40 and 32 via a zipper so that panel 42 can be removed orinserted in place to enable access and egress to the interior of theportable shelter 10.

As illustrated in FIG. 1, base structure 100 can be placed along asupporting surface and arranged such that rib intersections 110 alignwith a corresponding rib end from the portable shelter 10. Rib end 20 ais received by rib intersection 110 f Rib end 22 a is received by ribintersection 110 e. Rib intersection 24 a is received by ribintersection 110 d. Rib end 20 b is received by rib intersection 110 c.Rib end 22 b is received by rib intersection 110 b. Rib intersection 24b is received by rib intersection 110 a.

FIG. 2 shows portable shelter 10 in position over base structure 100.Panel 42 is folded over panel 32 to reveal the interior volume ofportable shelter 10. In the field, an assembler constructs the portableshelter 10 by arranging base structure 100 along the ground. Next, rib20, rib 22 and rib 24 are positioned in the base structure 100 byengaging a first rib end such as rib end 20 a in rib intersection 110 fand flexing rib 20 until rib end 20 b can be inserted into ribintersection 110 c. The flexed rib 20 is then placed on the ground inits flexed condition. Next, another rib end, such as rib end 22 a isinserted in rib intersection 110 e. Rib 22 is flexed until the opposingrib end 22 b can be inserted in rib intersection 110 b. The flexed rib22 is placed on the ground in its flexed condition. Thereafter, theremaining rib, rib 24 is added by placing rib end 24 a into ribintersection 110 d and flexing rib 24 until rib end 24 b can be insertedin rib intersection 110 a. After the ribs have been flexed, they can belifted and arranged close to one another above the ground in proximitywith the center of the area encompassed by the base structure 100 wherethey can be tied, clamped or otherwise connected to each other such thatthey remain standing above the ground.

Upon easily accomplishing the heretofore difficult task of arranging thesupport ribs for the portable shelter 10, the assembler arranges thevarious panel intersections over the ribs and connects the panelintersections to corresponding ribs with the provided hooks, ties, orhook and loop fasteners so that the base edge of each of the respectivepanels is proximally located to the base structure 100.

FIGS. 3 and 4 are schematic diagrams detailing the integration of asupporting rib and cover of a portable shelter at a select locationalong the base structure 100 of FIGS. 1 and 2. FIG. 3 shows rib end 24 aseparated from a first grommet 120 integrated with base structure 100and a second grommet 70 integrated with an extension strap 62. Rib end24 a includes probe 50, which fits within the corresponding openingsformed by grommet 120 and grommet 70. Once probe 50 engages grommet 120and grommet 70, extension strap 62 and cover strap 60 can be adjustedvia buckle 65 or some other tensioning apparatus to pull panel 32 andpanel 34 into position near base structure 100.

FIG. 5 is a schematic diagram illustrating the integration of asupporting rib of a portable shelter with an alternative base structure.As illustrated in FIG. 5, a secondary loop 130 with a correspondinggrommet 135 can be located at an appropriate position along basestructure 100 for receiving probe 50 of rib end 24 a. In the illustratedembodiment, secondary loop 130 is fixed to base structure 100 by sewingthe secondary loop 130 to the webbing as indicated by stitch pattern132.

FIG. 6 is a schematic diagram illustrating the integration of asupporting rib of a portable shelter with a third alternative basestructure. As shown in FIG. 6, a secondary loop 130 with a correspondinggrommet 135 can be sewn together via stitches 134 beyond the webbing ofbase structure 100, such that secondary loop 130 can be positioned asmay be desired along the length of base structure 100.

In still another embodiment (not shown), a secondary loop 130 can beformed absent a grommet. The secondary loop 130 can be fixed to the basestructure 100 as indicated in FIG. 5 or configured as shown in FIG. 6such that the secondary loop 130 can be manipulated along base structure100. As long as the secondary loop can be twisted to receive probe 50,no grommet is required. This alternative configuration would benefitfrom a slot or groove in probe 50 or near the intersection of probe 50and rib end 24 a to engage the secondary loop.

FIGS. 7-11 are schematic diagrams illustrating various embodiments of abase structure for portable shelters 10 that integrate with threesupport ribs. The base structures illustrated in FIGS. 7-11 are shown ina taught arrangement as if they were positioned by flexed ribs.

FIG. 7 includes base structure 700 made of a length of webbing sewntogether at junction 710 to form a primary loop. Rib intersectionsinclude grommets 120 strategically separated from their nearest neighborgrommets along the length of base structure 700. An uppermost segment100 a is defined by grommet 120 a and grommet 120 b. Moving in aclockwise rotation around base structure 700, segment 100 b is definedby grommet 120 b and junction 710. Segment 100 c is defined by junction710 and grommet 120 c. Segment 100 d is defined by grommet 120 c andgrommet 120 d. Segment 100 e is defined by grommet 120 d and grommet 120e. Segment 100 f is defined by grommet 120 e and grommet 120 f. Lastly,segment 100 g is defined by grommet 120 f and grommet 120 a. Asdescribed above in association with FIGS. 1 and 2, grommets 120 areseparated from their nearest neighbor grommets such that each of thegrommets can receive a respective rib end of a correspondingly arrangedportable shelter.

FIG. 8 includes base structure 800 made of a length of webbing coupledtogether at buckle 810 to form a primary loop. The addition of buckle810 permits easy adjustment of the length of base structure 800. Ribintersections include grommets 120 strategically separated from theirnearest neighbor grommets along the length of base structure 800.Additional grommets are integrated in the webbing to enable a user toselect the most appropriate grommet for receiving a probe to form adesired portable shelter. In this regard, grommets may be color coded,labeled or otherwise marked to indicate a set of grommets that can beused to support the ribs of a portable shelter. An uppermost segment 800a is defined by grommet 120 a and grommet 120 b with additional grommetsdisposed between the two. Moving in a clockwise rotation around basestructure 800, segment 800 b is defined by grommet 120 b and buckle 810.Segment 800 c is defined by buckle 810 and grommet 120 c. Segment 800 dis defined by grommet 120 c and grommet 120 d. Segment 800 e is definedby grommet 120 d and grommet 120 e. Segment 800 f is defined by grommet120 e and grommet 120 f. Lastly, segment 800 g is defined by grommet 120f and grommet 120 a. As with segment 800 a, each of the remainingsegments includes additional grommets between the end grommets thatdefine the segment. As described above in association with FIGS. 1 and2, grommets 120 are configured to receive a respective rib end of acorrespondingly arranged portable shelter. However, in the adjustableembodiment illustrated in FIG. 8 only a select number of the grommetsavailable will be used to support a rib end.

FIG. 9 includes base structure 900 made of a length of webbing 910 thatforms a primary loop. Rib intersections include grommets 135 insecondary loops 130 separated from their nearest neighbor grommets alongthe length of base structure 900. As described above, secondary loops130 can be arranged to slide along the length of webbing 910. Anuppermost portion is defined by secondary loop 130 a and grommet 135 aat a left most location and secondary loop 130 b and grommet 135 b at aright most location. Moving in a clockwise rotation around basestructure 900, an upper right side portion is defined by secondary loop130 b and grommet 135 b at an upper location and secondary loop 130 cand grommet 135 c at a lower location. A lower right side portion isdefined by secondary loop 130 c and grommet 135 c at an upper locationand secondary loop 130 d and grommet 135 d at a lower location. Alowermost portion is defined by secondary loop 130 d and grommet 135 dat a rightmost location and secondary loop 130 e and grommet 135 e at aleftmost location. A lower left side portion is defined at a lowerlocation by secondary loop 130 e and grommet 135 e at a rightmostlocation and secondary loop 130 f and grommet 135 f at a leftmostlocation. A last portion is defined by secondary loop 130 f and grommet135 f at a leftmost location and secondary loop 130 a and grommet 135 aat a rightmost location. As described above in association with FIGS. 1and 2, grommets 135 are separated from their nearest neighbor grommetssuch that each of the grommets can receive a respective rib end of acorrespondingly arranged portable shelter.

FIG. 10 includes base structure 1000 made of a length of cord 200. Cord200 may be tied to itself, crimped or otherwise coupled via a mechanicalcoupler. Rope, wire, cable, etc. can be used as substitutes for cord 200as long as the material used is arranged in a primary loop. Ribintersections include grommets 135 in secondary loops 130 strategicallyseparated from their nearest neighbor grommets along the length of basestructure 1000. As described above, secondary loops 130 can be arrangedto slide along the length of cord 200. An uppermost portion is definedby secondary loop 130 a and grommet 135 a at a left most location andsecondary loop 130 b and grommet 135 b at a right most location. Movingin a clockwise rotation around base structure 1000, an upper right sideportion is defined by secondary loop 130 b and grommet 135 b at an upperlocation and secondary loop 130 c and grommet 135 c at a lower location.A lower right side portion is defined by secondary loop 130 c andgrommet 135 c at an upper location and secondary loop 130 d and grommet135 d at a lower location. A lowermost portion is defined by secondaryloop 130 d and grommet 135 d at a rightmost location and secondary loop130 e and grommet 135 e at a leftmost location. A lower left sideportion is defined at a lower location by secondary loop 130 e andgrommet 135 e at a rightmost location and secondary loop 130 f andgrommet 135 f at a leftmost location. A last portion is defined bysecondary loop 130 f and grommet 135 f at a leftmost location andsecondary loop 130 a and grommet 135 a at a rightmost location. Asdescribed above in association with FIGS. 1 and 2, grommets 135 areseparated from their nearest neighbor grommets such that each of thegrommets can receive a respective rib end of a correspondingly arrangedportable shelter.

FIG. 11 includes base structure 1100 made of a length of webbing sewntogether at junction 1110 to form a primary loop. Rib intersectionsinclude grommets 120 strategically separated from their nearest neighborgrommets along the length of base structure 1100. An uppermost segment1100 a is defined by grommet 120 a and grommet 120 b. Moving in aclockwise rotation around base structure 1100, segment 1100 b is definedby grommet 120 b and junction 1110. Segment 1100 c is defined byjunction 1110 and grommet 120 c. Segment 1100 d is defined by grommet120 c and grommet 120 d. Segment 1100 e is defined by grommet 120 d andgrommet 120 e. Segment 1100 f is defined by grommet 120 e and grommet120 f. Lastly, segment 1100 g is defined by grommet 120 f and grommet120 a. As described above in association with FIGS. 1 and 2, grommets120 are separated from their nearest neighbor grommets such that each ofthe grommets can receive a respective rib end of a correspondinglyarranged portable shelter.

Base structure 1100 differs from base structure 700 (FIG. 7) in that theuppermost and lowermost segments have a length that is longer than theother segments. Other arrangements are possible as may be desired tosupport variously configured portable shelters.

FIG. 12 is a schematic diagram illustrating a base structure forportable shelters that integrates with four support ribs. FIG. 12includes base structure 1200 made of a length of webbing sewn togetherat junction 1210 to form a primary loop. Rib intersections includegrommets 120 strategically separated from their nearest neighborgrommets along the length of base structure 1200. An uppermost segment1200 a is defined by grommet 120 a and grommet 120 b. Moving in aclockwise rotation around base structure 1200, segment 1200 b is definedby grommet 120 b and grommet 120 c. Segment 1200 c is defined byjunction 1210 and grommet 120 c. Segment 1200 d is defined by junction120 and grommet 120 d. Segment 1200 e is defined by grommet 120 d andgrommet 120 e. Segment 1200 f is defined by grommet 120 e and grommet120 f. Segment 1200 g is defined by grommet 120 f and grommet 120 g.Segment 1200 h is defined by grommet 120 g and grommet 120 h. Lastly,segment 1200 i is defined by grommet 120 h and grommet 120 a. Asdescribed above in association with FIGS. 1 and 2, grommets 120 areseparated from their nearest neighbor grommets such that each of thegrommets can receive a respective rib end of a correspondingly arrangedportable shelter. Those skilled in the art will appreciate that variousbase structure configurations are possible. For example, base structureconfigurations that include more or less rib intersections.

FIG. 13 is a schematic diagram illustrating an adjustable length segment1300 or portion of a base structure. Member 125 d includes a channelthat encompasses a portion of a cable or wire used to form the primaryloop. Member 125 d further includes a tab with a hole suitablyconfigured for receiving a rib end. Member 125 e includes similarfeatures (i.e., the channel and tab) for receiving a different rib end.A first cable portion 1310, which traverses the channel of member 125 eis coupled to friction lock collar 1315. A second cable portion 1320,which traverses the channel of member 125 d is coupled to friction lockcollar 1325. Length “D,” or the distance along the primary loop definedby the location of the respective friction lock collars is adjusted byrotating the coupled portion of the friction lock collar towards thecloser of the two members to disengage the collar from the cable. Oncedisengaged, the friction lock collar can be adjusted along the length ofthe opposing cable. Once the friction lock collar is positioned wheredesired, the friction lock collar can be re-engaged along the opposingcable.

A method for constructing a flexible base structure 100 for a floorlessportable shelter 10 includes the steps of forming a continuous loop of aflexible material and arranging openings at respective locations alongthe continuous loop.

A method for providing a flexible base structure for a portable shelterincludes the steps of forming a continuous loop of a flexible materialand attaching rib intersections at respective locations along theflexible loop. Thereafter, the continuous loop can be placed along asurface to form a perimeter that closely approximates a base edge of adesired portable shelter.

Although disclosed embodiments use arrangements configured to engageflexible portable shelters that use three and four ribs to support afabric cover, it should be understood that alternative arrangements arepossible. For example, a flexible base structure can be configured toengage as few as two ribs and up to as many ribs as may be desired.

The foregoing description has been presented for purposes ofillustration and description. It is not intended to be exhaustive or tolimit the scope of the claims to the precise forms disclosed.Modifications or variations are possible in light of the aboveteachings. The embodiments discussed, however, were chosen and describedto enable one of ordinary skill to utilize various embodiments of thepresent flexible base structures and methods for constructing and usingthe same. All such modifications and variations are within the scope ofthe appended claims when interpreted in accordance with the breadth towhich they are fairly and legally entitled.

1. A base structure for supporting the ribs of a portable shelter,comprising: a flexible loop; a plurality of rib intersections arrangedalong the flexible loop, each of the plurality of rib intersectionsincluding an opening for receiving a respective end of a rib.
 2. Thebase structure of claim 1, wherein the flexible loop comprises amaterial selected from the group consisting of webbing, cord, rope, wireand cable.
 3. The base structure of claim 1, the flexible loop comprisesat least one length adjustable segment between adjacent ribintersections and at least one rib intersection comprises a memberarranged with a channel for receiving a portion of the flexible loop anda tab that encompasses the opening.
 4. The base structure of claim 1,wherein the rib intersections comprise respective grommets located atfixed locations.
 5. The base structure of claim 1, wherein the ribintersections comprise grommets fixed in a second loop formed ofwebbing, the second loop surrounding the flexible loop.
 6. The basestructure of claim 5, wherein the second loop is fixed to the flexibleloop.
 7. The base structure of claim 5, wherein the second loop isadjustable along the length of the flexible loop between nearestneighbor loops.
 8. A method for providing a flexible base structure fora portable shelter, comprising: forming a continuous loop of a flexiblematerial; and attaching a plurality of rib intersections at respectivelocations along the flexible loop.
 9. The method of claim 8, wherein theplurality of rib intersections comprise a respective secondary loop offlexible material that surrounds the continuous loop.
 10. The method ofclaim 9, further comprising: forming an opening in a secondary loop. 11.The method of claim 10, wherein forming an opening comprises inserting agrommet.
 12. The method of claim 8, further comprising: arranging thecontinuous loop upon a surface to form a perimeter that closelyapproximates a base edge of the portable shelter.
 13. A method forconstructing a flexible base structure for a floorless portable shelter,comprising: forming a continuous loop of a flexible material; andarranging a plurality of openings at respective locations along thecontinuous loop.
 14. The method of claim 13, wherein at least one of theopenings is formed with a grommet.
 15. The method of claim 13, whereinat least one of the openings is formed with a second loop of a flexiblematerial that surrounds the continuous loop, the second loop of flexiblematerial being substantially smaller than the continuous loop and largeenough to receive an end of a support rib.
 16. The method of claim 13,wherein at least one of the openings is formed with a second loop offlexible material that surrounds the continuous loop, the second loop offlexible material having a grommet.
 17. The method of claim 13, whereinarranging a plurality of openings at respective locations along thecontinuous loop comprises a set of fixed locations relative to eachother along the continuous loop.
 18. The method of claim 13, whereinforming a continuous loop of a flexible material comprises connecting afirst end of a length of the flexible material to a second end tocomplete the loop.
 19. The method of claim 18, wherein connectingcomprises sewing.
 20. The method of claim 18, wherein connectingcomprises coupling.